xml

package com.entry;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class Test {
	public static void main(String[] args) {
		//add();//添加
		delete();//删除
		try {
			update();
		} catch (ParserConfigurationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SAXException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (TransformerException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	//删除
	public static void delete() {
		try {
			// 1、得到DOM解析器的工厂实例
			DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
			// 2、从DOM工厂获得DOM解析器
			DocumentBuilder db = dbf.newDocumentBuilder();
			// 3、解析XML文档，得到一个Document，即DOM树
			Document doc = db.parse("book.xml");
			// 找到删除的节点
			NodeList list = doc.getElementsByTagName("book");
			for (int i = 0; i < list.getLength(); i++) {
				Element studentElement = (Element) list.item(i);
				String scoreID = studentElement.getAttribute("id");
				System.out.println(scoreID);
				if (scoreID.equals("bk104")) {
					//删除
					studentElement.getParentNode().removeChild(studentElement);
				}
			}
			// 保存XML文件
			TransformerFactory transformerFactory = TransformerFactory.newInstance();
			Transformer transformer = transformerFactory.newTransformer();
			DOMSource domSource = new DOMSource(doc);
			// 设置编码类型
			transformer.setOutputProperty(OutputKeys.ENCODING, "gb2312");
			StreamResult result = new StreamResult(new FileOutputStream("book.xml"));
			// 把DOM树转换为XML文件
			transformer.transform(domSource, result);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	//添加
	public static void add() {
		try {
			// 1、得到DOM解析器的工厂实例
			DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
			// 2、从DOM工厂获得DOM解析器
			DocumentBuilder db = dbf.newDocumentBuilder();
			// 3、解析XML文档，得到一个Document，即DOM树
			Document doc = db.parse("book.xml");
			// 创建book节点
			Element bookElement = doc.createElement("book");
			bookElement.setAttribute("id", "bk104");
			// 创建title节点
			Element titleElement = doc.createElement("title");
			titleElement.setTextContent("红楼梦");
			// 添加父子关系
			bookElement.appendChild(titleElement);
			// 创建author节点
			Element authorElement = doc.createElement("author");
			authorElement.setTextContent("曹雪芹");
			// 添加父子关系
			bookElement.appendChild(authorElement);
			// 创建price节点
			Element priceElement = doc.createElement("price");
			priceElement.setTextContent("30");
			// 添加父子关系
			bookElement.appendChild(priceElement);
			//找到根节点
			Element booksElement = (Element) doc.
					getElementsByTagName("books").item(0);
			booksElement.appendChild(bookElement);
			// 保存XML文件
			TransformerFactory transformerFactory =
				TransformerFactory.newInstance();
			Transformer transformer = transformerFactory
			.newTransformer();
			DOMSource domSource = new DOMSource(doc);
			// 设置编码类型
			transformer.setOutputProperty(OutputKeys.ENCODING,
					"gbk");
			StreamResult result = new StreamResult(
					new FileOutputStream("book.xml"));
			// 把DOM树转换为XML文件
			transformer.transform(domSource, result);
			System.out.println("添加成功");

		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	public static void update() throws ParserConfigurationException, SAXException, IOException, TransformerException{
		// 1、得到DOM解析器的工厂实例
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		// 2、从DOM工厂获得DOM解析器
		DocumentBuilder db = dbf.newDocumentBuilder();
		// 3、解析XML文档，得到一个Document，即DOM树
		Document doc = db.parse("book.xml");
		NodeList list = doc.getElementsByTagName("book");
		for (int i = 0; i < list.getLength(); i++) {
			Element bookElement = (Element) list.item(i);
			String scoreID = bookElement.getAttribute("id");
			System.out.println(scoreID);
			if (scoreID.equals("bk104")) {
				NodeList items=bookElement.getChildNodes();
				for (int j = 0; j < items.getLength(); j++) {
					Node node=items.item(j);
					if(node.getNodeName().equals("price")){
						node.setTextContent("2000");
					}
				}
			}
		}
		// 保存XML文件
		TransformerFactory transformerFactory =
		TransformerFactory.newInstance();
		Transformer transformer = transformerFactory.newTransformer();
		DOMSource domSource = new DOMSource(doc);
		// 设置编码类型
		transformer.setOutputProperty(OutputKeys.ENCODING,"gbk");
		StreamResult result = new StreamResult(
		new FileOutputStream("book.xml"));
		// 把DOM树转换为XML文件
		transformer.transform(domSource, result);
	   System.out.println("修改成功");			
	}
}